urho3d/Engine/Resource/Image.h

//
// Urho3D Engine
// Copyright (c) 2008-2012 Lasse Öörni
//
// Permission is hereby granted, free of charge, to any person obtaining a copy
// of this software and associated documentation files (the "Software"), to deal
// in the Software without restriction, including without limitation the rights
// to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
// copies of the Software, and to permit persons to whom the Software is
// furnished to do so, subject to the following conditions:
//
// The above copyright notice and this permission notice shall be included in
// all copies or substantial portions of the Software.
//
// THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
// IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
// FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
// AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
// LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
// OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
// THE SOFTWARE.
//

#pragma once

#include "ArrayPtr.h"
#include "Resource.h"

/// Supported compressed image formats.
enum CompressedFormat
{
    CF_NONE = 0,
    CF_DXT1,
    CF_DXT3,
    CF_DXT5,
    CF_ETC1,
    CF_PVRTC_RGB_2BPP,
    CF_PVRTC_RGBA_2BPP,
    CF_PVRTC_RGB_4BPP,
    CF_PVRTC_RGBA_4BPP,
};

/// Compressed image mip level.
struct CompressedLevel
{
    /// Construct empty.
    CompressedLevel() :
        data_(0),
        width_(0),
        height_(0),
        blockSize_(0),
        dataSize_(0),
        rowSize_(0),
        rows_(0)
    {
    }
    
    /// Decompress to RGBA. The destination buffer required is width * height * 4 bytes. Return true if successful.
    bool Decompress(unsigned char* dest);
    
    /// Compressed image data.
    unsigned char* data_;
    /// Compression format.
    CompressedFormat format_;
    /// Width.
    int width_;
    /// Height.
    int height_;
    /// Block size in bytes.
    unsigned blockSize_;
    /// Total data size in bytes.
    unsigned dataSize_;
    /// Row size in bytes.
    unsigned rowSize_;
    /// Number of rows.
    unsigned rows_;
};

/// %Image resource.
class Image : public Resource
{
    OBJECT(Image);
    
public:
    /// Construct empty.
    Image(Context* context);
    /// Destruct.
    virtual ~Image();
    /// Register object factory.
    static void RegisterObject(Context* context);
    
    /// Load resource. Return true if successful.
    virtual bool Load(Deserializer& source);
    
    /// %Set size and number of color components.
    void SetSize(int width, int height, unsigned components);
    /// %Set data.
    void SetData(const unsigned char* pixelData);
    /// Save in BMP format. Return true if successful.
    bool SaveBMP(const String& fileName);
    /// Save in TGA format. Return true if successful.
    bool SaveTGA(const String& fileName);
    
    /// Return width.
    int GetWidth() const { return width_; }
    /// Return height.
    int GetHeight() const { return height_; }
    /// Return number of color components.
    unsigned GetComponents() const { return components_; }
    /// Return pixel data.
    unsigned char* GetData() const { return data_; }
    /// Return whether is compressed.
    bool IsCompressed() const { return compressedFormat_ != CF_NONE; }
    /// Return compressed format.
    CompressedFormat GetCompressedFormat() const { return compressedFormat_; }
    /// Return number of compressed mip levels.
    unsigned GetNumCompressedLevels() const { return numCompressedLevels_; }
    /// Return next mip level by bilinear filtering.
    SharedPtr<Image> GetNextLevel() const;
    /// Return a compressed mip level.
    CompressedLevel GetCompressedLevel(unsigned index) const;
    
private:
    /// Decode an image using stb_image.
    static unsigned char* GetImageData(Deserializer& source, int& width, int& height, unsigned& components);
    /// Free an image file's pixel data.
    static void FreeImageData(unsigned char* pixelData);
    
    /// Width.
    int width_;
    /// Height.
    int height_;
    /// Number of color components.
    unsigned components_;
    /// Number of compressed mip levels.
    unsigned numCompressedLevels_;
    /// Compressed format.
    CompressedFormat compressedFormat_;
    /// Pixel data.
    SharedArrayPtr<unsigned char> data_;
};